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UNITED STATES PATENT ()FFICE. I

, ALBY o. WINN, 013 BOSTON, MASSACHUSETTS, ASSIGNOR or ONEHALF TO WILLIAM PAYNE, on SAME PLACE.

CA'LlPER-SQUARE;

SPECIFICATION aimin part of Letters Patent-No. 302,079,6lated July 15,1884.

I Application filed April 9.8, 1884. (No model.) i

To all whom it may concern.-

Be it known thatl, ALBY (l. WINN,"of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Caliper- Squares, of which the following .description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention has relation to measuringinstruments, and is shown embodied in a caliper-square wherein the bar or shank has a fixed jaw ,or rest, and is provided with a-movable jaw adapted to slide on the bar and to to hold the movable jaw in fixed position with relation to the said bar or shank, the threaded portion of the clamp being operated by a lever, substantially as hereinafter fully described, and particularly pointed out in the claims.

Figure 1 represents in plan view a calipersquare containing my invention; Fig. 2, a transverse section on the line, a a, Fig. 1,

through the slide of the movable jaw carrying the screw-threaded clamp; and Fig. 3, an end view of Fig. 1, looking in the direction of the arrow.

The bar or shank A has a fixed jaw or rest, a, at one end, and is provided with a slide, b, carrying a jaw, b, and provided with a setscrew, 0, for securing the slide at. any point to the bar A, the several parts being of any usualpreferred construction, and provided with suitable or usual scales or marks. A screwto engage the screw-rod on the bar or shank,

rod, cl, having an adjusting thumb -hut or wheel, d, is secured to the baror shank-A in the bearings 2 4, and passes through a slot, 3, in the slide 1). A clamp, 9, having a threaded portionto engage the threads of the screw rod, is attached to the slide b. The threaded portion of the clamp g, moved by a spring, acts as a halfnut and permits the .slide to be moved by the screw-rod to hold the slide to the rod; but when the clamp is moved to disengage the half-nut from the screw-rod the 5 5 said slide may be. freely and rapidly moved on the bar, and when nearly in the desired position the clamp will be released, in order that said clamp may again engage the screw-rod. When the slidecarrying the movable jaw is moved to the proper position, it may be locked there by the set-screw c. In the present instance the screw-rod partially rests in a groove in the bar or shank A, and the fastening project-ions of the bearing 4 are let into and flush 6 5' .with the face of said bar, to permit the slide 1) to be removed from the bar, the slot in the said slide receiving the screw-rod being enlarged to permit such removal. The bar or shank may be suitably graduated, and the adjusting nut or wheel may have finer graduations on its periphery, which, in connection with a pointer or indicator, 5, in the .end of the bar, enables a very fine anddelicate adjustment to be made. i

AS shown in Fig. 2, the clamp which engages the screw-rod consists, in the present instance, of a pivoted lever, 9, having the half-nut or screw-threaded portion 9" engaging the screw-rod and the thumb-plate g, which latter is acted upon by the spring h, to insure the engagement of the threaded portion g with the screw-rod.

To adjust the caliper-square shown'in the drawings, the clamp is disengaged from the screw-rod by pressing on'the thumb-plate thereof, the slide bodily moved on the bar to aboiit the point desired, the clamp released slide movable on the bar, and provided with the jaw b2 and spring-actuated clamp, the said clamp having a threaded portion adapted to engage the threads of the screw-rod, and a finger portion to permit said clamp to be disengaged from the screw-rod, substantially as described.

2. The shank or bar having the bearings 2 4, as described, and proyided with a screwrod having a thumb-nut, combined with a slide having inovenient- 011 the bar, and provided with a slot for the passage of the screwrod and larger than the bearing 4, as described, a spring-clamp having threads to 011- gage the screw-rod and lock the slide 011 the bar, as set forth.

3. The bar having the fixed jaw and pointer 5, and the screw-rod having bearings on the bar, and provided with the thumb-nut or adj usting-wheel with graduated periphery, as described, combined with a slide having movement on the bar, and provided with the jaw b, and the clamp 0, having a threaded portion to engage the screw-rod and lock the slide on the bar, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALBY C. XVINN.

\Vitnesses:

JOHN F. C. PREINKERT, Jlis. H. LANGE. 

